This application seeks core support for the Wisconsin Mental Retardation Research Center (MRRC). The Wisconsin MRRC, at the Waisman Center of the University of Wisconsin-Madison, is the focal point for the University of Wisconsin in the development of new knowledge about mental retardation and related developmental disabilities. The application seeks support for the Administration and Communications Core and five research support cores. The five research cores are the Computing, Data Management and Statistics Core, the Human Subjects Core, the Animal Care Core, the Pathology, Histology and Stereology Core, and the Brain Imaging Core. These cores provide essential, high-quality and sometimes unique services at costs that are below the rates for those services if purchased from outside the MRRC. This program will provide core support for 65 research projects to be conducted by 52 investigators in four research groups pursuing biomedical, behavioral and social research. The four research groups are the Molecular and Genetic Sciences Unit (MGSU), the Sensory and Cognitive Processes Unit (SMPU), the Communication Processes Unit (CPU), and the Social and Affective Processes Unit (SAPU). The research is designed to provide new information about the causes, nature, and possible efficacious intervention in disorders that cause mental retardation and other forms of developmental disabilities. Of the 65 projects, 53 are supported through extramural funding by current grants from the NIH and the NSF, 11 are supported by non-NIH grants, and one is being proposed as New Program Development.